Conventional laundering techniques for the cleaning and treatment of fabric articles such as garments have long involved both traditional aqueous-based washing and a technique commonly referred to as “dry cleaning”. Traditional aqueous based washing techniques have involved immersion of the fabric articles in a solution of water and detergent or soap products, followed by rinsing and drying. However, such conventional immersion cleaning techniques have proven unsatisfactory on a wide range of fabric articles that require special handling and/or cleaning methods due to fabric content, construction, etcetera, which may be unsuitable for immersion in water.
Accordingly, “dry cleaning” has been developed. Dry cleaning typically involves the use of non-aqueous, lipophilic fluids as the solvent or solution for cleaning. While the absence of water permits the cleaning of fabrics without the potential disastrous side effects water may cause, these lipophilic fluids do not perform well on hydrophilic and/or combination soils.
As a result, new methods have been developed wherein a lipophilic fluid is emulsified with water in order to better perform on these hydrophilic and/or combination soils. Along with this development, however, have arisen new problems. First, many lipophilic fluids have established “safe” exposure/inhalation limits. Second, the drying of items cleaned with the lipophilic fluid cannot be done automatically with the use of only a humidity sensor. Third, energy savings could be appreciated if the items to be dried are exposed to heat and tumbling only for time needed to achieve drying. This would also reduce heat and tumbling damage to the items. Lastly, because these lipophilic fluids possess far greater fouling capabilities than water alone as well as potential flash point problems, sensors typically used in clothes dryers may not be suitable for use in lipophilic fluid clothes dryers.
U.S. Pat. No. 6,122,480 (herein incorporated by reference) discloses a system for determining drying time in a clothes dryer that utilizes a humidity sensor. However, the present invention is directed to drying lipophilic fluid from fabrics—not water. Further, U.S. Pat. No. 4,111,034 (herein incorporated by reference) is directed to an apparatus for monitoring the solvent content of air in association with a dry-cleaning plant. The present invention is directed to detecting levels of several lipophilic fluids, some of which tend to foul sensors, in many environments, including the home.
Accordingly, the need remains for a system that controls a drying cycle in a drying apparatus by utilizing a gas sensor capable of sensing the concentration of lipophilic fluid vapor in the drying apparatus drum or a combination of sensors/condition detectors, at least one of which is capable of sensing the concentration of lipophilic fluid vapor in the drying apparatus drum.